Preventive effects of diphenyl dimethyl dicarboxylate on the immunotoxicity of carbon tetrachloride in ICR mice.

To investigate the preventive effects of diphenyl dimethyl dicarboxylate (PMC) on the immunotoxicity of carbon tetrachloride (CCl4) in ICR mice, PMC (3 and 6 mg/kg, respectively) were orally administered to mice through a zonde once a day for 28 consecutive days. CCl4 solution was also administered at 1 ml/kg (25%) p.o. 2 hr later the administration of PMC twice a week. Mice were immunized and challenged with sheep red blood cells (SRBC). Immune function were evaluated by humoral, cell-mediated and non-specific immune responses. The results of this study were summarized as follows; 1. The body weight gains and the relative spleen and thymus weights were significantly increased by PMC treatment as compared with treatment of CCl4 alone. However, the relative liver weights were significantly decreased. These values were similar to those of control mice. 2. Hemagglutination (HA) titers were significantly enhanced by PMC treatment as compared with treatment of CCl4 alone. Plaque forming cells (PFC) were also greatly increased by PMC treatment, especially at a dose of 6 mg/kg of it. 3. Delayed-type hypersensitivity (DTH) response was significantly decreased in mice treated with CCl4 and PMC along with the increase of PMC doses, as compared with those in the mice treated with CCl4 alone, while rosette forming cells (RFC) were significantly increased. These results were similar to those of control mice. 4. In PMC treatment as compared with treatment of CCl4 alone, there were significant increases in activities of natural killer (NK) cells and phagocytes along with circulating leukocytes. These results suggest that PMC has significant preventive effect on CCl4-induced immunotoxic status.